Critical micelle concentration (CMC) of lecithin and lysolecithin was measured according to the electric conductivity method and the fluorescence method. Lecithin presented no distinct CMC in either alcohol solution or water suspension, but lysolecithin showed clear CMC by those two methods as follows : 0.08×10-4 mol in water at 20°C, 0.62×10-4 M in water at 30°C and 0.125×10-4mol in alcohol at room temperature by the measurement of electric conductivity, and 0.125×10-4mol in water, 0.14×10-4mol in alcohol both at room temperature by the fluorescence method.
Present research was carried out with the intention of finding the kinds of compounds formed by the action of 30% H2O2 on di-basic fatty acid esters. The sample used was di-methyl ester of succinic-, adipic- and sebasic acid, and reacted without catalyst. By reacting 0.1mol of ester with 2.2mols of 30% H2O2 under the condition of 105° C and 30 hours, it was recognized that the various lower mono- and di-basic fatty acids and lower carbonyl compounds were produced. Fixed quantity of carbon dioxide that produced by these reactions, and from these values, it was recognized that the lower esters were readily reactive than the higher homologue, and di-basic fatty acid esters were more readily oxidized than the mono-basic fatty acid esters.
About the composition of the saturated fatty acids in cuttle-fish oil, only palmitic acid was found by M. Tsujimoto and H. Kimura. The saturated fatty acids were measured by fractional precipitation of Pb salts from ethanol and by steam distillation of the brominated methyl esters* and by oxidation of the methyl esters in acetone with KMnO4. The saturated fatty acids were contained about 25% in fatty acids of cuttle-fish oil and myristic, palmitic, stearic and arachidic acids were isolated by fractional distillation of the saturated methyl esters. Besides, by paper chromatography the small quantities of capric, lauric and behenic acids were recognized, and it is also supposed to contain the very small quantities of caproic and caprylic acids. At the same time, there are many studies about this, but their results are not so sure and detailed as mine.
In order to obtain an available separation method of polyunsaturated fatty acid fractions from cuttle fish oils, following several procedures were comparatively tested; 1) separation by lithium salts from acetone, 2) crystallization from acetone at low temperatures, 3) distillation through spinning band rectifying column at reduced pressure, 4) fractionation by urea adducts of fatty acids from methanol, 5) fractionation by urea adducts of methylesters. The separation efficiency of these procedures was determined by paper chromatography of reversed phase system consisted of acetonitrile/glacial acetic acid (7/5) as mobile solvent and hydrocarbon as stationary phase and by the yield of polyethenoid fractions. In the case of the fractionation by urea adducts of methylesters, all of the saturated and lowly unsaturated fractions were removed at room temperature from methanol solutions, and then the highly unsaturated fractions were given at 0°C in the form of adducts. The separation efficiency was the best of five in this case.
(1) The characteristics of the lipids (acetone-soluble lipid, lecithin, cephalin and sphingolipid) obtained from barracuda, Sphyraena pinguis GÜNTHER, were studied from the view point of fat metabolism of fish. (2) Forty-one fresh sample fish caught in the Komekami fishing ground near Odawara City (west part of Kanagawa Prefecture, Japan) on the 4th of October, 1959, were extracted with acetone. The acetone extract was further treated with acetone to yield the fatty oil as acetone-soluble lipid.The above mentioned fish, previously treated with acetone, were successively extracted with ethanol, petroleum ether and finally with boiling ethanol to yield lecithin fraction, cephalin fraction and sphingolipid fraction as shown in Fig. -1. (3) The acetone-soluble lipid was obtained in the yield of 0.50% from the fresh fish. This lipid had the characteristics as given in Table-3. The unsaponifiable material contained 21.38% of sterols. The conjugated fatty acids, prepared from the acetone-soluble lipid by alkali-hydrolysis, were separated into three portions, solid, slightly unsaturated and highly unsaturated acids, with a combination of lead salt-ethanol and lithium salt-acetone fractionations. Individual acids were identified with paper chromatography, saturated acids and hydrogenated polyenoic acids as their 2, 4-dinitrophenylhydrazones, and mono-and dienoic acids as their mercuric acetate complexes. The paper chromatography indicated the presence of myristic, palmitic, stearic, arachidic, behenic, zoomaric, oleic, eicosenoic, erucic and linoiic acids in the acetone-soluble lipid. The composition of the conjugated fatty acids of the acetone-soluble lipid was found to be as shown in Table-9. According to brief calculation, the acetone-souble lipid from barracuda contains 22.9% saturated acids, 55.2% mono-and dienoic acids and 21.9% polyenoic acids (trienoic 6.0%, tetraenoic 7.8%, pentaenoic 5.7% and hexaenoic acid 2.4%). (4) Lecithin purified from the lecithin fraction mentioned above was obtained in the yield of 0.14% from the fresh barracuda. The characteristics of the purified lecithin are shown in Table-10. The conjugated fatty acids, prepared from the lecithin by alkali-hydrolysis, were separated into solid and liquid fatty acids by the lead salt-ethanol method modified by HILDITCH. Spectro-photometry of the alkali-isomerized liquid fatty acids indicated the presence of conjugated tri-to pentaenoic acids in the lecithin. According to simple calculation, the composition of the conjugated fatty acids of the lecithin from the sample fish seems to consist of 34.2% saturated acids and 65.8% unsaturated acids. (5) Cephalin purified from the above mentioned cephalin fraction with petroleum ether was obtained in the yield of 0.60% from the fresh sample fish. Fractional precipitation of the purified cephalin from chloroform with absolute ethanol yielded five groups and showed the presence of phosphatidyl serine, phosphatidyl ethanolamine and inositol-containing lipid in the cephalin from the sample fish. The characteristics of the fractionated cephalins are summarized in Table-11. The conjugated fatty acids, prepared from the cephalin by alkali-hydrolysis, were separated into two portions (solid and liquid acids) by the lead salt-ethanol fractionation. Spectrophotometry of the alkali-isomerized liquid fatty acids showed no presence of polyenoic acids. According to rough calculation, the conjugated fatty acids of the cephalin from the sample fish consist of 40.4% saturated acids and 59.6% of unsaturated acids. It shows that the component fatty acids of the lecithin are more unsaturated than those from cephalin.
The amount adsorbed of sodium dodecyl sulfate and dodecylammonium chloride on carbon black versus equilibrium concentration curves were measured and the results were correlated with the suspendability of the carbon black particles in the surfactants solutions under the same conditions. It is found that the correlation of the amount adsorbed with the suspendability is not necessarily valid. At the low equilibrium concentrations dodecylammonium chloride does not act to disperse the carbon particles, whereas the adsorption is fairly greater for dodecylammonium chloride than for sodium dodecyl sulfate. With both surfactants, the suspendability-concentration curves show a steeper increase immediately below the concentration at which adsorption attains saturation, and the formation of stable suspention of the carbon particles is observed in the range of saturation, probably owing to the effect of orientation of adsorbed ions at the solid surface. From the another measurement on the relationships between suspendability and concentration obtained in surfactants solution such as sodium dodecyl sulfate, dodecyl pyridinium bromide and dodecyltrimethylammonium chloride, it is evident that the suspending power of both anionic and cationic surfactants is rather reduced at their higher concentrations.